Vented containers for flowable substances are, of course, known. For the purposes of the present invention, a flowable substance will be understood to be a liquid of greater or lesser viscosity or a flowable pulverulent or fine granular substance.
The term "venting device" is here used to mean a device which allows pressure equalization between the interior of the container and the ambient exterior thereof, i.e. which limits superatmospheric pressure build-up in the container as well as the development of subatmospheric pressures therein. A pressure build-up or a subatmospheric pressure can develop, for example, when the volume of the flowable medium in the container changes with, for example, temperature. The fluctuations in the volume of the mass within the container cause the package to "breathe" through the venting device. Containers with such venting devices are also used for adhesives.
A container of the basic type described above can have, at a lower portion of a side wall, a discharge opening and a venting device in the top wall. In the simplest case, the venting device is provided as a bore of small diameter in a cover which can be screwed onto a collar surrounding an opening, e.g. a filling opening, in the top wall of the container. During the "breathing" of the contents of the container with such a system, however, it is not possible to exclude the passage of contaminants or water into the interior.